Sometimes you have to make sure that only one instance of a shell script is running at the same time.
For example a cron job which is executed via crond that does not provide
locking on its own (e.g. ...

Question
I'd like to be able to run a UNIX command precisely every second over a long time period.
I need a solution, which does not lag behind after a certain time, because of the time the command ...

How can I run a cron command with existing environmental variables?
If I am at a shell prompt I can type echo $ORACLE_HOME and get a path. This is one of my environmental variables that gets set in ...

I have a script that I want to be able to run in two machines. These two machines get copies of the script from the same git repository. The script needs to run with the right interpreter (e.g. zsh).
...

A few years ago I setup a cron job to automatically ping a URL every minute as part of a monitoring system (that's oversimplification, but it'll do for this question). Because I'm a horrible person, I ...

This is a RedHat Enterprise Linux 5 system (RHEL). We manage this system using Cfengine.
We have several cronjobs which are running twice as often as usual. I checked the cronjobs under /etc/cron.d/ ...

I'm setting up a Cronjob that will backup a MySQL database I have in my server, but I don't want it to keep overwriting the same file over and over again. Instead, I want to have an array of backups ...

I've done quite a bit of research in how to do this, and I see there's no direct way in cron to run a job, say, every other Thursday.
Right now, I'm leaning toward making a script that will just run ...

I want to add a cron entry that does something like:
00 00 * * * * /tmp/script.sh
Is there something I can add to the end of the line, so that when it is finished, it will remove the line out of my ...

Is there a way to "query" a crontab to find which cron jobs run at some arbitrary date/time, or during a certain range of times?
For example, determine which will be run at sometime between 14:00 and ...

I am aware of a lot of pitfalls in the magic world of crontabs, but sometimes it would help troubleshooting a lot when you have some smart way to enter an interactive (bash) shell with exact identical ...

Ok, so I've just had a read through this page after a way to improve my current backup solution on my Debian server. Tar seems to be offering a quite nice multi-volume feature, although when I try it ...

I'm running CentOS 5.5.
We have several cronjobs stored in /etc/cron.daily/ . We would like the email for some of these cronjobs to go to a particular email address, while the rest of the emails in ...